package com.example.demo99.Mapper;

import com.example.demo99.Entity.Product;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;

@Mapper
public interface ProductMapper {
    Product findById(Integer id);  // 查商品

    // 减库存
    void decreaseStock(@Param("productId") Integer productId, @Param("quantity") Integer quantity);

}
